Hyperbaric support

Tunnel Boring Machines (TBM) are used to excavate tunnels in loose soil.

At their forward points, these machines are equipped with cutting heads which cut through rock and soil. The cutting blades must be replaced regularly to ensure the TBM operates correctly.

To ensure the stability of soft soil during excavation, the cutting head is pressurised. This means that maintenance work done to replace cutting blades is conducted by qualified personnel using work techniques and procedures applicable to pressurised environments.

Conducting work in such hyperbaric environments is very similar to underwater work. Technicians breathe compressed air which means they must observe decompression phases that vary in length according to the length of their exposure and the pressure sustained.

To optimise working time at the cutting head and deliver support to prior assessments, we have developed specific techniques and procedures dedicated to TBM cutting head maintenance work.

Dry hyperbaric environments :

We use dry hyperbaric environments for maintenance work on TBM cutting heads.

These techniques are derived from underwater work techniques, the difference being that the teams operate in compressed air environments rather than underwater. This requires that procedures, techniques and protective equipment be adapted to the compressed air environment (dry hyperbaric).

For projects requiring long periods of work in pressurised environments, we can deploy our saturation systems. We own our own saturation systems for use on this type of work and specifically suited to TBM requirements.

Our teams are trained in :

  • – Working on the TBM cutting head at pressures above 3 bar
  • – Performing maintenance work such as the replacement of cutting wheel

To conduct projects using saturation systems, we provide a full saturation system that than house 8 hyperbaric technicians.

Hydrokarst therefore delivers a full hyperbaric support service, based on :

  • – Qualified professional teams (hyperbaric technicians) with Class 2 and 3 qualifications, sections A and D
  • – Efficient and specific equipment
  • – Strict procedures to ensure safety, deadlines and quality of work
  • – Robust experience in work underwater, via rope access and in confined spaces.

« Hyperbaric Works » certification :

As part of tunnel boring machine interventions, our company is certified “Hyperbaric works” in accordance with the 29th September 2017 decree’s requirements.